(Not Applicable)
(Not Applicable)
The present invention generally relates to methods of forming parts, and more particularly to an improved method of forming a finished part through the use of a tool generated via a computer aided design system.
The concept of rapid prototyping in commercial and military applications is well known. Rapid prototyping may have wide variety of applications in the aerospace industry, substantially extending to all forms of structural and manufacturing related operations. More specifically, rapid prototyping procedures are frequently used in manufacturing parts related to the field, namely, in construction and assembly of complex and sophisticated structures such as aircrafts or other forms of vehicles. Thus, rapid prototyping has become a vital and integral process in the aerospace industry, as well as other related industries.
More specifically, rapid prototyping maybe used during product development to verify design concepts and to conduct further testings therefrom. Typically, the design concepts generated for such purpose are developed based on engineering specifications. Depending on the set of engineering specifications, a particular design concept may be created. The engineering specifications will usually include the necessary product and design information so that the depicted illustration may portray an actual finished product to the highest precision and accuracy as possible.
In particular, the design may be created in any medium. However, a computer aided design system is generally used. When the design is generated in the computer aided design system, such design may be stored therein so that it may be retrieved later in time for reuse or be modified to reflect any subsequent design changes.
Moreover, rapid prototyping procedures may also incorporate the concept of stereolithography technology. As disclosed in U.S. Pat. No. 4,575,330 issued on Mar. 11, 1986, stereolithography generally refers to a method of rapidly fabricating a three-dimensional object (e.g., a prototype tool) in a layer by layer fashion. Stereolithography technology traditionally involves a laser beam that may be directable by computer control, such as the computer aided design system as described above.
The laser beam may be positionable relative to a photopolymer resin medium. The laser beam may traverse across the resin medium to selectively cure the resin to form the three-dimensional object through the accumulation of incremental layers of cured resin. Specifically, upon exposure to the laser beam, the resin may rapidly polymerize, or solidify. Thus, rapid prototyping procedures oftentimes meld computer modeling techniques with the actual creation of three-dimensional models.
However, rapid prototyping procedures have their share of limitations. Even though the application of rapid prototyping procedures has proved to be invaluable in certain industries, the resin models that result therefrom are generally characterized as having less strength than the strength of materials designated for the finished parts. Therefore, the resin models produced via stereolithography have been utilized for visualization purposes to verify production intent, rather than for functional usage.
In addition, the finished parts may further need to be adapted to correspond to a selected work surface, such as an aircraft structure. The finished parts and the work surface must be complimentary or compatible with each other to maximize their intended utilities. However, the finished parts and the work surface are often incompatible with each other due to their respective complex geometries and configurations. Simply put, the finished parts, after enduring through arduous manufacturing, may not match their intended target, namely, the work surface. Such occurrence would diminish their utility, or even render them useless.
Even if the finished parts match or conform to the work surface, the cycle and labor time that must be expended to accomplish such purpose may be significant. Furthermore, the expense to provide the sized and conformed finished parts may be considerable. For example, such parts may further need to be defined to be attached to the work surface. A plurality of tooling tasks, such as drilling, sanding, cutting, bending or the like, may be necessary for adaptation to the work surface. The tooling tasks upon the finished parts may be done by trial-and-error process to achieve the desired arrangement to the work surface. Such process may require repetition and tedious toil. Thus, the resulting time and expense may be burdensome in view of the overall scheme.
When the work surface is marked by complex geometries and configuration, a direct adaptation approach of the finished parts thereto may be difficult and troublesome. As stated above, the work surface and the finished parts need to be strategically arranged with respect to each other to fully achieve their intended purposes when united. For instance, the finished parts oftentimes need to be specifically arranged in relation to the work surface. However, the engagement therebetween may be difficult due to the complex geometries and configuration of one of them, or even both. Thus, further time and expense may be inevitable in order to desirably adapt the finished part to the work surface.
Thus, there has long been a need in the industry, and in the aerospace industry in particular, for a method of forming a finished part that is sized and configured to properly engage a corresponding work surface utilizing computer modeling and stereolithography technology. In particular, there is a need to form the finished part without performing post-machining in order to achieve cost-saving and efficient manufacturing thereof.
The present invention addresses and overcomes the above-described deficiencies by providing a method that utilizes computer modeling and stereolithography technology to mitigate post-machining of the formed finished part. More specifically, an initial part is adapted for engagement to a stereolithographically-created tool for performing a desired tooling task thereupon to form the finished part that is conformable to the work surface. In this respect, not only does the present invention mitigate the need to use expensive post-machining, but it also minimizes labor and cycle time of forming the finished part.
In accordance with the present invention, there is provided a method of forming a tool for performing a desired tooling task upon an unfinished part to form a finished part. The method may comprise the step of creating a computer model of the tool corresponding to the unfinished part. Moreover, the method may further comprise using the computer model to stereolithographically create the tool.
Thereafter, the unfinished part maybe engaged to the tool to facilitate the performance of the desired tooling task upon the unfinished tool to form the finished part. The engaged tool and the unfinished part may be representative of an intermediate assembly.
More specifically, a computer aided design system may be accessed to retrieve the computer model of the tool corresponding to the unfinished part. In the alternative, tool parameters maybe derived to define the tool. The tool parameters maybe derivable to correspondingly size and configure the tool to the unfinished part. In addition, the tool parameters may be inputted into a computer aided design system. The tool parameters may be chosen from the group consisting of geometrical dimensions, size, thickness, texture, durability, shock resistance, dimensional stability, material characteristic, producibility, and combinations thereof.
In accordance with the methods employed in the present invention, there may further be a stereolithography apparatus. The computer model in the computer aided design system may be translated into tool commands for transmission, or communication, to the stereolithography apparatus. Such apparatus may comprise an irradiation source and a liquid medium, preferably photopolymer resin medium. The irradiation source may be responsive to the transmitted tool commands to move over the liquid medium that selectively transforms to a physical state upon exposure the irradiation source.
Furthermore, the tool may define a geometrical configuration. The unfinished part may be positioned in abutting contact to the tool. More particularly, the geometrical configuration of the tool may be adapted to receive the unfinished part when being positioned thereto. The unfinished part may be secured to the geometrical configuration of the tool after being positioned thereto for performing the desired tooling task thereupon to form the finished part.
In addition, the unfinished part may be manufactured by using the computer aided design system. More specifically, a computer model of the unfinished part may be created. Furthermore, the computer model of the tool may be created through the use of the computer model of the unfinished part. Or, in the alternative, a conventional factory manufactured unfinished part may be obtained. Part parameters defining the unfinished part may be derived to be inputted into the computer aided design system. There may further comprise a computer aided manufacturing machine, such as a computer numeric control system. The inputted part parameters may be used to formulate part commands for transmission, or communication, to the computer aided manufacturing system.